KR20100043464A - Cr free cu alloys and its manufacturing method with high electrical conductivity and high tensile strength - Google Patents

Abstract

PURPOSE: A copper alloy without chrome including high electrical conductivity and high tensile strength and a manufacturing method thereof are provided to obtain an environment-friendly metal. CONSTITUTION: A copper alloy without chrome including high electrical conductivity and high tensile strength contains 0.3~0.9 weight% of iron, 0.1~0.6 weight% of cobalt, 0.01~0.10 weight% of magnesium, 0.1~0.5 weight% of phosphorus, and copper. The conductivity of the copper alloy without chrome including high electrical conductivity and high tensile strength is over 75% IACS. The room temperature tensile strength of the copper alloy is over 530 mega pascals.

Description

Cr free Cu alloys and its manufacturing method with high electrical conductivity and high tensile strength

The present invention relates to a high-k conductivity and high-strength copper alloy, in particular, by excluding the environmental pollutant chromium (Cr) and alloying only with environmentally friendly metals, the alloyed copper alloy has excellent electrical conductivity of 75% IACS or more and excellent tensile strength of 530MPa or more The present invention relates to a sustainable high conductivity and high strength copper alloy and a method of manufacturing the same.

In general, materials used in casting molds, welding electrodes, and electrode parts for electric discharge machining require excellent electric conductivity of 75% IAC (International Annealed Copper Standard) and excellent tensile strength of 530 MPa or more.

As a material satisfying the above characteristics, a copper alloy containing 0.4 to 1.2% by weight of chromium (Cr) is known.

By the way, the chromium (Cr) is a substance in which the working environment and the air emission allowable concentration are regulated in the Ministry of Labor's Industrial Safety and Health Act and the Ministry of Environment's atmospheric environment conservation law.

Therefore, in order to cope with environmental regulations related to such harmful substances, development of environment-friendly materials that can replace copper alloy materials containing chromium (Cr), which is used until now, is urgently required.

On the other hand, in order to increase the electrical conductivity of the metal, it is necessary to minimize the influence of the factors that contribute to the strengthening of the metal, that is, the fraction of the second phase, such as the amount of alloying elements added, plastic processing and precipitates, intermetallic compounds. However, in this case, there is a problem that the tensile strength of the metal is lowered.

On the contrary, when the metal is reinforced by various reinforcing mechanisms such as solid solution strengthening, precipitation strengthening, processing strengthening and dispersion strengthening in order to increase the tensile strength of the metal, lattice of solid solution, vacancy, dislocation, etc. A defect (Lattice defect) is introduced or a second phase such as a precipitate, an intermetallic compound is introduced, there is a problem that the electrical conductivity of the metal is lowered.

First, the precipitation-reinforced alloy may not only have high tensile strength but also excellent heat resistance by dispersing and depositing fine precipitates in a matrix, but the electrical conductivity is lowered by the alloying element that is dissolved, and thus it is difficult to obtain high electrical conductivity.

In addition, the process-reinforced alloy can maintain a higher electrical conductivity than other reinforcement mechanisms, and high strength can be obtained by dislocations introduced into the matrix structure of the alloy during plastic working, but it is easily softened by recrystallization to secure heat resistance. The disadvantage is that you can't.

In addition, the solid-solution-reinforced alloys (Cu-P, Cu-Ni, Cu-Ag, Cu-Cd) have an extremely low electrical conductivity and hardly obtain high strength depending on the type and amount of alloying elements.

Among the solid-solution-reinforced alloys, the Cu-Ag alloy has high electrical conductivity of 90% IACS or more and has excellent heat resistance, but is a material used for high conductivity and heat-resistant parts, but there is a disadvantage that silver (Ag), which is an additional element, is expensive. .

The Cu-Cd alloy has high electrical conductivity, tensile strength, excellent heat resistance, and the like, but the cadmium (Cd) is defined as a carcinogen and an environmentally harmful substance.

Therefore, there has been a need for an environmentally friendly metal that can increase the tensile strength while minimizing the decrease in the electrical conductivity of the metal. Although many studies have been made until now, it has replaced the copper alloy material containing chromium (Cr). Copper alloys satisfying excellent electrical conductivity and tensile strength have not been developed.

The present invention has been made to solve the above problems, and does not contain chromium (Cr) as a hazardous substance, has a high electrical conductivity of 75% IACS or more, and has a high electrical conductivity to satisfy the requirements of having a tensile strength of 530MPa or more and It is an object of the present invention to provide a high strength copper alloy and its manufacturing method.

High conductivity and high strength copper alloy according to the present invention for achieving the above object is 0.3 to 0.9% by weight of iron (Fe), 0.1 to 0.6% by weight of cobalt (Co), 0.01 to 0.10% by weight of magnesium (Mg), phosphorus ( P) 0.1-0.5 weight% and remainder are copper (Cu), and are high electric conductivity and high strength copper alloy which does not contain chromium whose electrical conductivity is 75% IACS or more and normal temperature tensile strength is 530 Mpa or more.

In addition, the method of manufacturing a high-k conductivity and high-strength copper alloy according to the present invention is 0.3 to 0.9% by weight of iron (Fe), 0.1 to 0.6% by weight of cobalt (Co), 0.01 to 0.10% by weight of magnesium (Mg), phosphorus (P) 0.1 ~ 0.5% by weight and the remainder by the solution composition of the copper (Cu) solution solution for 1 hour at a temperature of 920 ℃, aged for 3 hours at a temperature of 480 ℃ after cold rolling at a rolling rate of 20% It is possible to produce a copper alloy having an electrical conductivity of 75% IACS or more and a room temperature tensile strength of 530MPa or more.

The copper alloy according to the present invention configured as described above is a copper alloy composed of Cu-Fe-Co-Mg-P, and does not contain chromium (Cr), which is an environmentally harmful substance, and has an electrical conductivity of 75% IACS or more and excellent of 530 MPa or more. There is an effect that can be used in a variety of materials, such as casting molds, welding electrodes and electrical discharge machining electrode components that require tensile strength.

In addition, the copper alloy according to the present invention can obtain the same level of electrical conductivity and tensile strength as compared to the existing chromium-based copper alloy.

The high electroconductivity and high strength copper alloy according to the present invention are high electroconductivity and high strength copper alloy composed of iron (Fe), cobalt (Co), magnesium (Mg), phosphorus (P) and copper (Cu).

The iron (Fe) is 0.3 to 0.9% by weight, the cobalt (Co) is 0.1 to 0.6% by weight, the magnesium (Mg) is 0.01 to 0.10% by weight, the phosphorus (P) is 0.1 to 0.5% by weight and the copper (Cu) is composed of remainder.

In addition, the method of manufacturing a copper alloy of the present invention comprises the steps of forming a composition of the alloy with iron (Fe), cobalt (Co), magnesium (Mg), phosphorus (P) and copper (Cu), and to prepare a copper alloy with the composition It consists of steps.

That is, the present invention improves tensile strength while maintaining excellent electrical conductivity by adding an alloying element capable of forming an intermetallic compound between alloying elements according to the respective composition amounts, thereby uniformly dispersing fine intermetallic compounds in a known metal. Provide copper alloys.

High conductivity and high strength copper alloy according to the present invention is 0.3 to 0.9% by weight of iron (Fe), 0.1 to 0.6% by weight of cobalt (Co), 0.01 to 0.10% by weight of magnesium (Mg), 0.1 to 0.5% by weight of phosphorus (P) and The balance is composed of copper (Cu), the reason for the addition and content of each alloying element is as follows.

Although iron (Fe) has a large drop in electrical conductivity in the solid solution to copper (Cu), the electrical conductivity of copper (Cu) can be improved by forming an intermetallic compound by reacting with phosphorus (P) by precipitation strengthening heat treatment. In addition, it is an alloy element that can improve tensile strength together.

The iron (Fe) is contained in the 0.3 ~ 0.9% by weight, if the iron content is less than 0.3% by weight can not obtain the strength increase effect, if the iron content is more than 0.9% by weight can sufficiently obtain the strength increase effect, but This is because the conductivity drops below 75% IACS.

Cobalt (Co) has a large drop in electrical conductivity in the solid solution to copper (Cu), but the electrical conductivity of copper (Cu) can be improved by forming an intermetallic compound by reacting with phosphorus (P) by precipitation strengthening heat treatment. In addition, it is an alloy element that can improve tensile strength together.

The cobalt (Co) is contained 0.1 ~ 0.6% by weight, the cobalt (Co) content is less than 0.1% by weight can not obtain the effect of increasing the tensile strength, if the content of cobalt (Co) is more than 0.6% by weight tensile This is because the effect of increasing the strength can be sufficiently obtained, but the electrical conductivity drops below 75% IACS.

Magnesium (Mg) deoxidizes in the molten copper and reacts with phosphorus (P) by precipitation strengthening heat treatment to form an intermetallic compound, which not only improves the electrical conductivity of copper (Cu) but also improves tensile strength together. Alloy element.

The magnesium (Mg) is contained 0.01 ~ 0.10% by weight, if the content of magnesium (Mg) is less than 0.01% by weight can not obtain the effect of increasing the tensile strength, if the content of magnesium (Mg) is 0.1% by weight or more Conductivity drops below 75% IACS.

Phosphorus (P) deoxidizes in molten copper and decreases the electrical conductivity in solid solution to copper (Cu), but reacts with iron (Fe), cobalt (Co), and magnesium (Mg) by precipitation strengthening heat treatment. By forming an intermetallic compound, not only can the electrical conductivity of copper (Cu) be improved, but also an alloy element that can improve tensile strength together.

The phosphorus (P) is contained in 0.1 to 0.5% by weight, if the content of phosphorus (P) is less than 0.1% by weight can not obtain the effect of increasing the tensile strength, if the content of phosphorus (P) is 0.5% by weight or more Conductivity drops below 75% IACS.

Hereinafter, a preferred embodiment of the present invention will be described in detail with respect to the high conductivity and high strength copper alloy containing no chromium (Cr) according to the present invention.

In order to manufacture the copper alloy according to the present invention, the alloy having the composition shown in Table 1 was prepared by a conventional melt stirring copper alloy manufacturing method.

That is, an alloy having the composition shown in Table 1 was dissolved in the air using a high frequency melting furnace, and then cast into a mold at a temperature of 1,200 ° C. to prepare a billet having a diameter of 160 mm and a length of 500 mm.

The billet was hot-extruded at a temperature of 850 ° C. and processed into a sheet having a width of 55 mm and a thickness of 14 mm. The billet was melted for 1 hour at a temperature of 920 ° C., and then aged for 3 hours at a temperature of 480 ° C. After that, cold rolling was performed at a rolling rate of 20% to obtain a test piece.

The test on the test piece and its method are as follows.

First, tensile strength was measured with a tensile tester, electrical conductivity was measured with a conductivity meter, and hardness was measured with a Rockwell hardness tester.

TABLE 1

Alloy (% by weight) Fe Co Mg P Cr Cu Example One 0.54 0.14 0.036 0.21 99.08 2 0.72 0.12 0.058 0.30 98.82 3 0.60 0.25 0.025 0.26 98.85 4 0.88 0.24 0.028 0.33 98.54 Comparative example 5 0.28 0.13 0.012 0.14 99.41 6 0.28 0.24 0.039 0.18 99.25 7 0.21 0.37 0.029 0.23 99.10 8 0.22 0.70 0.034 0.32 98.67 9 0.90 99.10

TABLE 2

alloy Tensile Strength (N / mm ² ) Electrical Conductivity (% IACS) Hardness (HRB) Example One 536 83 83 2 539 76 84 3 536 80 84 4 540 78 83 Comparative example 5 482 84 83 6 502 84 82 7 502 75 84 8 553 72 83 9 530 75 83

As shown in Table 2, 0.3 to 0.9% by weight of iron (Fe) according to the present invention, 0.1 to 0.6% by weight of cobalt (Co), 0.01 to 0.10% by weight of magnesium (Mg), 0.1 to 0.5% by weight of phosphorus (P) % And remainder of the copper alloy alloyed by the composition ratio composed of most of the copper (Cu) and trace impurities, the electrical conductivity is 75% IACS or more, the room temperature tensile strength of 530MPa or more, while the composition ratio of the present invention The comparative examples (except for copper alloys containing chromium) have an electrical conductivity of 75% IACS or more but a tensile strength of 530 MPa or less, or a tensile strength of 530MPa or more but an electrical conductivity of 75% IACS or less and an electrical conductivity of 75% IACS or more. At room temperature, tensile strength of more than 530MPa was not displayed at the same time.

The high electroconductivity and high strength copper alloy according to the present invention have been described above. The technical configuration of the present invention will be understood by those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features.

Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive, the scope of the present invention being indicated by the following claims rather than the foregoing description, and the meanings of the claims and All changes or modifications derived from the scope and equivalent concepts thereof should be construed as being included in the scope of the present invention.

Claims (2)

In the high electroconductivity and high strength copper alloy used for welding electrodes and electrodes for electric discharge machining, 0.3-0.9% by weight of iron (Fe), 0.1-0.6% by weight of cobalt (Co), 0.01-0.10% by weight of magnesium (Mg), 0.1-0.5% by weight of phosphorus (P), and the balance by copper (Cu), High-conductivity and high-strength copper alloys containing no chromium, characterized in that the electrical conductivity is 75% IACS or more, and the tensile strength at room temperature is 530 MPa or more. In the manufacturing method of high electroconductivity and high strength copper alloy used for welding electrode and electrode for electric discharge machining, 0.3-0.9% by weight of iron (Fe), 0.1-0.6% by weight of cobalt (Co), 0.01-0.10% by weight of magnesium (Mg), 0.1-0.5% by weight of phosphorus (P) and the balance of copper (Cu) The solution was melted for 1 hour at a temperature of 920 ° C., and aged for 3 hours at a temperature of 480 ° C., followed by cold rolling at a rolling rate of 20%. The electrical conductivity was 75% IACS or more, and the normal temperature tensile strength was 530 MPa. A method for producing a high-strength conductivity and high-strength copper alloy containing no chromium characterized by producing the above-described copper alloy.